EPC91118 GaN motor driver design

Once again, the company is using three of its 100V 15Arms EPC23104 monolithic half-bridge ICs, which include power transistors, drivers and level-shifting.

Power dissipation is minimised by the 8.7mΩ (typ) on-resistance of the driver ICs.

EPC91118 GaN motor driver design

The board is called EPC91118, and its specification is 15 to 55V, 10Arms and 21Apeak while installed on the back of a motor in a robot wrist.

The 32mm board is delivered in a 55mm frame (see photos) that includes connectors and screw locations to fit directly onto a motor (left) that EPC has yet to name (Electronics Weekly has asked, so watch this space if it is important to you).

Also on the 32mm PCB are RS485 communications, a 5Vout dc-dc converter, a 3.3Vout LDO, and current sensing for two of the three output phases.

The MCU is an STM32G431CBU6 and the magnetic encoder outputs 1,024 pulses over 360°.

Due to the high operational frequency that GaN allows – the PWMs run at 100kHz with 50ns dead-time – electrolytic capacitors have been eliminated from the circuits, said company CEO Alex Lidow. The DC-link only uses ceramic capacitors.

Use in drones is also expected.

EPC’s EPC91118 product page can be found here EPC suggests buying the board from Digi-Key.